Display devices including light guides are known in the prior art. For example, U.S. Pat. No. 4,113,360 discloses an indicating device for displaying symbols. The device is characterised by a plate of fluorescent material having metallized edges to create a light trap for the light created in the plate, a layer of light dispersing material mounted in spaced relation to a surface of the plate, contact film disposed at least in selected areas between the layer and plate and means for selectively moving portions of the layer into optical contact with the contact film and plate which causes emergence of the fluorescent light from the plate.
U.S. Pat. No. 6,525,483 discloses an improved device in which a complete display of pixels can be formed that can be addressed using column and row addressing. The display device has row and column electrodes, a movable element and means for supplying voltages to the electrodes. This structure is shown on a rigid glass support.
Manufacturing glass column plates is a difficult task and must be done batch wise. The relief structures on the column plate can be made by laser etching a suitable substrate, but this is a relatively high-energy slow process. The laser ablation also creates dust which must be removed before the device can be constructed.